Thank you! I've noticed some nice lacing on a few of the my blues, I'm happy to know it's a "good" thing, not just something I find pretty.I will give you the best example I heard. Birds that are blue should have nice edging or lacing on the feathers. So if you breed blues with that it will also be in your black birds..... they are genetically different. People cross them all the time but it messes up your blues if you use a bird from a black pen and vice versa. Also blues tend to be silver based (it just makes the best blues) and black birds tend to be gold based. Those are just some examples.